Magnetotransport and dielectric properties of Bi-containing La 0.6 Sr 0.15 Bi 0.15 Mn 1.1-x B x O 3-δ rare-earth manganites with B = Cr, Fe, Co, Ni

The effect of the replacement of manganese by Spions of transition metals on the structural, microstructural, dielectric, and magnetotransport properties of nonstoichiometric La 0.6 Sr 0.15 Bi 0.15 Mn 1.1-x B x O 3-δ compositions with B = Cr, Fe, Co and Ni (0 ≤ χ ≤ 0.3) was investigated. It is shown that in all compositions a weak change for the lattice parameter of the rhombohedral perovskite structure is observed. It is established that the real structure is defective and contains cationic V (c) and anionic V (a) vacancies. With increasing χ, an increase in the resistivity and the absence of a metal-semiconductor phase transition for χ > 0.20 are observed. The electron-phonon interaction constant /ph was determined. The most significant change in the structural and functional properties was observed for the compositions with B = Fe, for which constant γ ph ≈ 7.7 achieves a maximum value. At χ = 0.05, an increase in magnetoresistance effect of the tunnel type is observed.